Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
World J Microbiol Biotechnol. 2013 Aug;29(8):1487-97. doi: 10.1007/s11274-013-1314-4. Epub 2013 Mar 19.
Bacillus megaterium encapsulated in calcium alginate microcapsules was prepared and tested for its efficacy against sheath blight disease of rice. In laboratory conditions, the aqueous suspension (1:100, v/v in potato dextrose agar) of the bacterial microcapsules (10(10) spores/ml) inhibited mycelial growth of Rhizoctonia solani (>99 %) after the microcapsules were produced and stored for 12 months at room temperature (28 ± 2 °C). The survival of the bacterium in the microcapsules in response to ultraviolet (u.v.) irradiation and high temperature was investigated. The survivability of the bacterium in the encapsulated form was greater than that of the fresh cells when it was subjected to u.v. (20-W General electric u.v. lamp from a 25 cm distance for 48 h) and a high temperature treatment (80 °C for 48 h). Cells of the bacterium were detected by scanning electron microscope on both the leaf sheath and the leaf blade (in pot tests in a greenhouse) after spraying encapsulated product. The number of bacteria on the surface of both rice tissues (5 Log. number/g of plant) after spraying with encapsulated product was not significantly different from that after spraying with fresh cells onto the rice seedlings. Spraying the encapsulated B. megaterium on rice plants in the greenhouse was as effective as spraying a chemical fungicide for suppressing rice sheath blight disease.
用海藻酸钙微胶囊包埋巨大芽孢杆菌，并测试其防治水稻纹枯病的效果。在实验室条件下，将细菌微胶囊的水悬浮液（在马铃薯葡萄糖琼脂中 1:100，v/v）（10(10)个孢子/ml）在室温（28±2°C）下生产和储存 12 个月后，抑制立枯丝核菌的菌丝生长（>99%）。研究了微胶囊中细菌对紫外线（u.v.）照射和高温的生存能力。与新鲜细胞相比，在封装形式下，细菌的存活率在紫外线（距 25 cm 处使用 20-W 通用电气紫外线灯照射 48 h）和高温处理（80°C 处理 48 h）时更高。在温室盆栽试验中，用扫描电子显微镜检测到了叶鞘和叶片上的细菌细胞（喷洒封装产品后）。在喷洒封装产品后，水稻组织表面的细菌数量（每克植物 5 Log.数量）与喷洒新鲜细胞后没有显著差异。在温室中向水稻植株喷洒封装的 B. megaterium 与喷洒化学杀菌剂防治水稻纹枯病一样有效。
